The invention relates to the production of metallic oxides, and more particularly, to the production of such oxides under "mild" reaction conditions, to form grain sizes in the range from 0.2 to 100 microns, in addition to their production in the form of transparent or opaque coatings.
There is a need for a wide variety of metallic oxides. They are used as transparent electrical conductors, superconductors, electrochromic materials and catalysts. They are also used for battery electrodes and electrolytes, coatings, paints, membranes and ceramic bodies. The available production methods for such oxides are not entirely satisfactory.
Generally, metallic oxide production is by hydrothermal reactions of metal salts, metal alkoxides, and sol-gels, followed by pyrolysis. These methods involve material degradation, and the inclusion of different chemical compositions in the bulk material phase. Other methods use RF (radio frequency) sputtering from compact metal oxide targets; CVD (chemical vapor deposition) or plasma processes in volatile metal oxide precursor compounds; or high temperature pyrolysis of metal-organic compounds. These methods have drawbacks such as possible inclusion of impurities due to energetic and high temperature environments, undesired residues, and associated high processing costs, as well as environmental and personnel hazards.
Accordingly, it is an object of the invention to facilitate and simplify the production of metallic oxides, and to realize oxide compositions at low cost, avoiding many of the objections associated with prior and current methods.
Another object of the invention is to deposit metallic oxides at a comparatively low temperature, while simultaneously maintaining a comparatively high rate of deposition. A related object is to facilitate the depositions in thin film form.
A further object of the invention is to achieve electroactive oxide deposits with controlled thickness or particle size. A related object is to achieve controlled thicknesses which have increased uniformity of thickness.
A still further object of the invention is to achieve the deposit of metal oxides on general substrates with prescribed a real configurations.